A flat X-ray detector conventionally has a scintillator that converts incident X-rays into light, and a light converting layer with detector elements that receive (pick up) the light from the scintillator and emit electrons for producing an image data value of the detector elements.
In the predecessor of the flat X-ray detector, the image intensifier, it was possible to measure the dose during the recording of an image, and so it was possible to control the image dose for recording an image.
Flat X-ray detectors have not so far themselves been capable of dose measurement. In the prior art, a dose measuring chamber is arranged in front of the flat X-ray detector. Such a typical chamber has three to five measurement fields, and is based on semiconductor technology. A disadvantage of such a chamber resides in that under certain circumstances it can be visible on the finished X-ray image. In order to avoid this, DE 103 13 602 A1 presents an absorption structure that is applied to a film backing and is very thin. This structure is also arranged between the X-ray tube and the flat X-ray detector.